While there is no shortage of British films whose attempts at a gritty crime milieu crumble under the weight of mockney clich and over-the-top bloodbaths, the best depictions of crime are to be found in movies with wider, social realist ambitions - Ken Loach's My Name Is Joe and Sweet Sixteen among them. While writer/director Paul Andrew Williams isn't attempting a Loach movie, his debut feature London To Brighton does achieve a similar synthesis of compassionate realism and dramatic tension. Indeed, this very auspicious debut will have you on the edge of your seat.

The film opens with the adrenalin already racing, as a 20-something prostitute, Kelly (Lorraine Stanley), deposits panic-stricken 11-year-old Joanne (Giorgia Groome) in a public lavatory, while she performs the tricks - a pulverised eye notwithstanding - needed to fund a dawn train out of London. While they escape to Brighton, Kelly's odious pimp gets a call from a gangland boss, who knows why the woman and girl have fled, and wants them back.

What follows is lean, and terribly mean. If only more thrillers were as direct. We believe the world on screen - one populated by street prostitutes, pimps and vagrants; bottom-feeders whose lives are soaked in desperation - and care for Kelly and Joanne terribly. The fact that this is a film in which a grim fate for them is entirely plausible, makes that sympathy painfully felt.

For the first 10 minutes of Flushed Away, I was a little concerned that Aardman, the creators of Wallace & Gromit, had lost their touch. In fact, I just needed to make the emotional adjustment required to accept rats as the main characters of a children's animated adventure. It's a bit of a leap, but Aardman sweeten the pill by adding a mouse as the hero and giving all its rodents distinctly human physical characteristics. And once it gets moving, it's a hoot.

The tale concerns mouse house-pet Roddy St James, voiced by Hugh Jackman but with the gait and air of a Hugh Grant, who is flushed from his cushy Kensington home into the drains below London. There he falls for sewer boat captain Rita (Kate Winslet), tackles diabolical villain The Toad (Ian McKellen) and finds life can be sweet among the stinking detritus. The voice work is excellent, the action has all the pace and madcap incident of the Wallace & Gromit films, there are some terrific musical numbers and, most of all, the jokes come thick, fast and arch. My favourite is a rat heavy's forlorn reminiscence: "I used to work in a lab, up top."

American director John Cameron Mitchell follows Hedwig And The Angry Inch with another possible cult classic. Shortbus should, I suppose, be controversial, because it is rammed with explicit sex - straight sex, gay sex and orgies. But it isn't, partly because we're getting bored with such controversy, mostly because its sex scenes are incredibly funny (notably the gay three-way with a very special rendition of the Star Spangled Banner) and fit the film's bittersweet reflection on that age-old dilemma of how to "connect".

However open-minded Mitchell's New York protagonists are, what they can't seem to do is feel: either physically, as in the case of the sex therapist who's never had an orgasm; or emotionally, as with the gay couple who embark on the key signifier of the emotionally deficient - the open relationship. What strikes one more than the eye-popping sexual content and colourful milieu, is that these unhappy people do not feel the need to hurt each other in the course of solving their problems. It is a remarkably good-hearted film, and very welcome for that.

Rarely has a movie title played with fire quite so forlornly. Big Nothing is exactly that: a big, fat zero, a would-be comedy crime caper that is painfully unfunny, with all the imagination of a dog chasing its tail. David Schwimmer is, indeed, in hangdog Friends mode, and utterly underwhelming as a loser lured into an incompetent blackmail attempt by his call centre co-worker. The latter is played by Shaun Of The Dead's Simon Pegg, who is presumably fine-tuning his American accent in readiness for better things.

All films are out now